Rotary cutter



Sept. 19, 1939. A. GEITNER May 7 1937 11v VENTOR 6E/77VER ALEXA/VDERL TTORNE Y Patented Sept. 19, 1939 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to rotary cutters such as milling cutters, end mills, hollow mills etc., and has for its principal object to provide such a cutter with simple but eflicient combined adjusting and locking means for the cutter blades thereof.

A further object of this invention is to provide a cutter with easily adjusted locking means with which the blades may be accurately and. rigidly j: held in place in the cutter.

Another object of this invention is to incorporate part of the locking means in the cutting blades of the cutter.

All these and other objects and attendant advantages of the invention will become more readily apparent from the detailed description thereof which follows, reference being had to the accompanying drawing in which Figure 1 is a front elevation and partial section of a rotary cutter provided with my novel adjusting and locking means, the section being taken on the line l:cl:r of Figure 2.

Figure 2 is a side elevation and partial section of the rotary cutter, the section being taken on the line 2:13-2a: of Figure 1.

Figure 3 is a detail perspective view of one of the cutter blades used in the rotary cutter illustrated in Figures 1 and 2.

Figure 4 is a front elevation of a rotary cutter provided with a slightly modified form of the adjusting and locking means for the cutter blades thereof.

Figure 5 is a side elevation and partial section of the rotary cutter, the section being taken on the line 5:r5:c of Figure 4.

Figure 6 is a detail perspective View of one of the cutter blades used in the cutter illustrated in Figures 4 and 5.

In the several figures of the drawing like reference numerals indicate like parts.

The novel adjusting and locking feature for the cutter blades of rotary cutters forming the subject matter of my present invention provides for such cutters an easy and quick manner of changing the cutter blades and an accurate adjustment thereof before the blades are rigidly locked in place.

As illustrated in the various figures of the drawing the blade holder l of the rotary cutter is in the form illustrated in Figure 1 provided in its periphery with a series of cutter grooves 2, 2 which extend the full length of the holder to have the cutting blades 3, 3 adjustable endwise therein. The grooves are uniform in depth and width so that when the cutter blades are inserted they are uniformly held to project from the periphery and I 1 front of the blade holder. Each cutter groove 2 has in one of its walls a locking groove 4 which extends from the front of the blade holder to within a short distance of the rear thereof to provide a shoulder 5 at one end of the groove to have the adjusting screw 6 rest thereagainst as will hereinafter appear.

Eiach locking groove has a cylindrical wall which is partially cut away by the cutter groove and the greater portion of the surface of the locking member 1 is correspondingly cylindrical so as to accurately slide in the locking groove with part of the outer wall of the locking member projecting from the locking groove into the cutter groove. Because of the cylindrical bearing provided by the locking groove the locking member can also rock in the groove so that it will adjust itself radially when it is forced against the cutter blade. The projecting portion of the looking members is faced off so as to taper toward the forward end and into the tapering surface are cut a series of longitudinally extending serrations 8, 8.

The portion of one side of the cutter blade, which is engaged by the locking member, is correspondingly faced off so as to taper toward the rear of the cutter blade and into this tapering surface of the cutter blade are cut the serrations 9, 9.

The cutter blade 3 is inserted into the holder by sliding it into the front of the cutter groove so as to have its serrations 9, 9 engage the serrations 8, 8 in the locking member for a preliminary radial adjustment of the cutter blade in the cutter groove. Threaded thru the locking member and normally resting against the shoulder 5 is the adjusting screw 6 so that by rotating this screw the locking member may be forced forwardly in its locking groove to have the tapering serrated surfaces of the cutter blade and locking member brought into binding contact with each other to rigidly hold the cutting blade against radial and endwise displacement in the cutter groove. The tapering binding surfaces are arranged so that end pressure against the cutting blade will tend to increase the binding engagement between the blade and its locking member which will keep the cutting blade accurately positioned in the blade holder during its cutting operation.

As illustrated in Figures 1 and 2 the front of the blade holder is provided with a cylindrical recess II] in order that the bottom of the cutting blades may project thereinto so that with suitable cutting edges provided on the inwardly projecting portions of the cutter blades the blade holder of the rotary cutter may be used as a hollow mill.

In Figures 4, and 6 I have illustrated a slightly modified form of my invention in which the binding surface of the cutter blades l2, I2 is not tapered so that the serrations l3, I3 out thereinto are parallel with the Walls of the cutter grooves in which the cutter blades are mounted. However in this modified form the locking groove 14 is angular to the cutter groove so that as the locking member I 5 is moved forward in the locking groove by its adjusting screw l6 it is gradually forced against the side of the cutter blade into binding engagement therewith. The contact surface of the locking member, which is provided with the serrations H, I! is faced off parallel with the sides of the cutter groove so as to provide a binding engagement with the cutter blade the full length of the locking member.

I claim:

1. A cutter having a cylindrical body with a hollow center extending, into one end and a shank extending from the other end, cutter grooves extending longitudinally of the cylindrical body from one end to the other end thereof and from the inside of the hollow center to the outside of the cylindrical body, a locking groove adjacent each of said. cutter grooves intermediate the outside and the inside thereof and extending partially the length of the cylindrical body from one end thereof so as to provide a shoulder therein, radially and longitudinally movable cutting blades in said cutter grooves so as to project from the periphery and one end of the cylindrical body, longitudinally extending serrations on one side of said cutting blades substantially parallel to the axis of rotation of the cutter, a wedge member movable in each of said locking grooves, an adjusting screw threaded thru each of said wedge members so as to rest against the shoulder at the inner end of the locking grooves for the movement of the Wedge member and longitudinal serrations in said Wedge members for engagement with the serrations of said cutting blades so as to provide a locking of the cutting blades in variable radially and longitudinally projecting positions from said cylindrical body.

2. A cutter structure as set forth in claim 1 in which the cutting blades are provided with a cutting edge on the inside adjacent the outer cutting edge thereof and extend from the inner wall of the hollow center of the cylindrical body toward the center thereof.

3. A cutter as set forth in claim 1 in which said serrations in said cutting blades are inclined from one end of the blades.

ALEXANDER L. GEITNER. 

